Forget any preconceptions you may have had about earthworms as solitary free-thinking individuals.

Recent studies at the University of Liege have revealed that annelids can communicate by touch and make "group decisions" regarding their movements. Researchers placed earthworms in chambers and discovered that their choice of exits was not random - they preferred to move together. Subsequent trials suggested that the sense of touch rather than chemical trails governed the decisions:

After the worm chose its route to the food... the second worms were no more likely to take the same route as their predecessors. This indicated that the worms did not leave a chemical trail behind them that communicated their direction of travel. Yet if two worms were placed together at the start of the maze, they were more likely to follow one another, suggesting that they used touch to communicate where they were going.

Further details at the BBC link, where the copyeditor used "herd" to describe a group of worms. Most compilations of collective nouns suggest that the proper venereal term is "clew," as in "Unifying Democrats is like trying to herd a clew of worms."

This gives us the opportunity to insert the "cat herding" commercial for EDS, which ran during the Super Bowl a decade ago. With apologies to those who feel that the content here should be restricted to new material, here is the commercial which, inexplicably, has apparently never been posted at Neatorama.